Campaigners against sex slavery have welcomed the move by one of the largest newspaper publishers in the UK to ban advertisements for "adult services" from its titles - almost 300 publications, including 17 dailies and websites.

Writing in the Croydon Guardian last week, Andy Parkes, group editor at Newsquest South London, said: "The company has taken a decision no longer to publish adult services advertisements, either in print or on its websites. Increasing concerns regarding the appalling issue of human trafficking have been significant in this decision, which is effective immediately."

Newsquest's head office would not elaborate on the decision or the possible impact on advertising revenue, but campaign groups have welcomed the move. Members of the Croydon Community Against Trafficking posed as punters answering ads. In a Society Guardian report last year, it revealed that 84% of women being sold for sex were from overseas, most of them trafficked.

A CCAT spokesman says: "We are pleased that Newsquest has had the boldness to lead in an industry that has historically been complicit in the trafficking of women by allowing these victims to be sold via adverts."

Natalia Dawkins, assistant chief executive of the Poppy Project, which campaigns to get women out of prostitution, says: "This is an important first step towards... disrupting the buying of sex and related services. We commend Newsquest for acknowledging the harm caused to women and highlighting the fact that prostitution is not a victimless crime. We hope this action will encourage other publishers to do the same."